Fixed Phase Delay Compensation Phase Shifter for Simple Microstrip Implemenation

This paper introduces a concept for a fixed phase digital phase shifter based on band pass delay compensation networks for moderate bandwidth, low-cost/no-tune microstrip applications, which on the other hand require high accuracy. Closed form formulas for synthesis are presented along with considerations for optimal selection of the available degrees of freedom. With respect to previous concepts (Ref.[1]-[5]) this concept consumes less space, requires lower impedance range, has low sensitivity and is highly accurate. A 6-bit phase shifter for rapid frequency translation with 20% bandwidth around 4 GHz was synthesized and physically implemented. Measurements showed excellent results of less than +/-1° of phase accuracy and frequency translation performance around the theoretical limits.